The first step of the process is an interview with a person from HR. The interviewer was really nice and he seemed to be more aware of the how the engineering teams work than regular HR people. The interview was conducted in english even though we were both Portuguese. He gave good feedback in the end and asked whether I would prefer to do an interview onsite during 3h with 3 different interviewers, or take on a programming challenge (for which I would have 1 week to do) plus two 45min interviews in different days onsite. I opted for the 2nd option and did the backend engineering challenge, which I enjoyed a lot. After a few weeks I received an email saying that I would not continue the process and that they could provide more detailed feedback about the challenge. Obviously, I asked for more details, because I had spent one entire week doing the challenge. I wanted to, at least, learn something from this experience. They replied saying that "there was nothing particularly wrong" with my solution, but they were looking for someone very senior and had no room for mid-level people (I had 10y of experience). After a few weeks, I noticed on LinkedIn that they had hired two junior people for this position. In summary, they should really improve the feedback they give to the people who spend considerable amount of time doing the challenges, and avoid giving made up excuses to candidates. At least if they really want to be different than other companies...